zim message: "Looks like you found a bug" when trying to search "not found"

[Robin Lee]

https://bugzilla.redhat.com/show_bug.cgi?id=826886

Description of problem:
If I call the zim search function (CtrlShiftF), enter "not found" in the search line and press "Find", the I get an error popup:

==============================================================
Looks like you found a bug

AttributeError: 'set' object has no attribute 'scores'

When reporting this bug please include
the information from the text box below
===============================================================

The "text below" is
--------------------------------------------------
This is zim 0.56
Python version is sys.version_info(major=2, minor=7, micro=3, releaselevel='final', serial=0)
Gtk version is (2, 24, 10)
Pygtk version is (2, 24, 0)
Platform is posix
Zim revision is:
  branch: pyzim-trunk
  revision: 533 <email address hidden>
  date: 2012-04-02 22:07:22 +0200

======= Traceback =======
  File "/usr/lib/python2.7/site-packages/zim/gui/searchdialog.py", line 94, in _search
    self.results_treeview.search(string)
  File "/usr/lib/python2.7/site-packages/zim/gui/searchdialog.py", line 179, in search
    self.selection.search(self.query, callback=self._search_callback)
  File "/usr/lib/python2.7/site-packages/zim/search.py", line 249, in search
    self.update(self._process_group(query.root, selection, callback))
  File "/usr/lib/python2.7/site-packages/zim/search.py", line 340, in _process_group
    cont = callback(results, None)
  File "/usr/lib/python2.7/site-packages/zim/gui/searchdialog.py", line 186, in _search_callback
    self._update_results(results)
  File "/usr/lib/python2.7/site-packages/zim/gui/searchdialog.py", line 215, in _update_results
    score = results.scores.get(path, 0)
AttributeError: 'set' object has no attribute 'score
-----------------------------------------------------------------------

Version-Release number of selected component (if applicable):
Zim-0.56-1.fc17.noarch

How reproducible:
always

Steps to Reproduce:
1.See description
2.
3.

Actual results:
See description

Expected results:
No such error msg

Additional info: